Terrariums, those beautiful, often intricate mini gardens encapsulated in glass, have seen a surge in popularity recently. If you’ve ever found yourself captivated by the aesthetic artistry of creating a tiny garden within a closed terrarium, you know that there’s more to it than meets the eye.
Closed terrariums are not just visually pleasing, they’re tiny, self-sustaining ecosystems filled with life. When you add creatures and animals to your terrarium, it becomes an enclosed civilization; a vibrant, active world that you can observe, admire, and learn from.
Today, we’re going to explore the transformative magic that comes with adding the right creatures to your closed terrarium. Here are the top 10 best animals and insects that will not only keep your terrarium clean and healthy but will also bring it to life in a way that’s truly mesmerizing.
Top 10 Terrarium Inhabitants
Here are the 10 best animals and insects you can introduce to a closed terrarium:
- Cherry shrimp
- Darkling beetles
- Pill bugs
- Dwarf white isopods
- Amphipods
- Pond snail
- Ramshorn snails
- Springtails
- Earthworms
- Millipedes
Before we dive into specifics, there are a few important points to keep in mind:
- Vertebrates cannot survive in closed terrariums. They need space, ventilation, and a lot of attention and care that a closed ecosystem can’t provide.
- Not all animals and insects can live in a completely sealed terrarium. Unless your terrarium is very large with plenty of plants, most will require supplementary food like fruits. While the animals on our list can mostly fend for themselves, it’s still recommended to treat them every now and then.
Cherry Shrimp

Neocaridina davidi, better known as the Cherry Shrimp, is a colorful freshwater shrimp native to Taiwan. Highly adaptable, they have become a favorite addition to aquariums and closed terrariums worldwide. These small crustaceans come in various shades of red, with the deepest red being the most coveted. The Cherry Shrimp adds a touch of vibrant color to any terrarium, creating a lively scene against the green plants. In terms of diet, they primarily feed on algae, biofilm, and decaying plant matter, making them excellent additions to a closed terrarium ecosystem.
Cherry shrimps are perfect for adding to a sealed terrarium with a small water feature. They can thrive in a live terrarium with a pond-like setup within a 2.5 or 5-gallon container, providing a small but significant contribution to keeping the algae population under control. This, combined with their low maintenance and non-demanding nature, makes them an ideal terrarium animal. Keeping cherry shrimps adds an aquatic element to your terrarium and fosters an enclosed ecosystem that is both dynamic and fascinating to observe.
Darkling Beetles

The Darkling Beetle (Zophobas morio) is a creature that thrives in calm, enclosed environments. Known as super worms in their larval stage, they are a fantastic addition to a terrarium ecosystem, acting as efficient decomposers. Within a closed terrarium, these beetles require only a small depth of soil and high terrarium walls to feel at home. They feed on fresh and decaying vegetation, making them an effective cleanup crew for your terrarium and helping keep your terrarium ecosystem healthy.
Including darkling beetles in your insect terrarium requires a bit of care. While they are generally low maintenance, it’s crucial to remove any uneaten food as it may lead to the growth of mold in the terrarium. Mold can cause an imbalance in your closed terrarium, posing a risk to your terrarium pets. Thus, managing the diet of these beetles and regular maintenance is key to keeping a healthy animal terrarium with darkling beetles.
Pill Bugs

Pill Bugs, also known as roly-polys or potato bugs, are another excellent choice for a bug terrarium. They are natural decomposers that require a moist environment, high humidity, and a hiding place like a piece of wood in your terrarium to thrive. These creatures play a critical role in a closed terrarium ecosystem as they feed on decaying plant matter, thereby contributing to nutrient cycling.
Not only are they fascinating to watch as they curl up into a tight ball when threatened, but they also serve a practical role in a closed terrarium. Their preference for moisture and decay helps maintain the balance in a terrarium, preventing excess waste buildup, and mitigating the risk of mold growth. For enthusiasts who are still learning how to make a closed terrarium, the inclusion of pill bugs is a practical and beneficial step.
Dwarf White Isopods

Dwarf White Isopods are the unsung heroes of the terrarium world. Being among the smallest species of isopods, they are a popular choice for terrarium pets among enthusiasts. Though often hidden from sight due to their shy and burrowing nature, their bright white color adds an unexpected element of contrast to a terrarium. They are resilient, prolific breeders, making them a reliable cleanup crew in your closed terrarium.
These isopods play a pivotal role in the terrarium ecosystem. They feed on decaying matter, thereby preventing waste buildup and contributing to the overall health of a closed terrarium. Given their small size, they are an excellent choice for any sized terrarium, but they do particularly well in smaller, enclosed terrariums. Consider adding Dwarf White Isopods to your terrarium for animals, especially if you aim for a balance between aesthetics and functionality.
Amphipods

Amphipods are small crustaceans that are fantastic additions to a closed terrarium. They feed on decaying matter and algae, significantly contributing to maintaining your terrarium’s cleanliness. These creatures are highly adaptable, with the capability to adjust to various environmental conditions making them excellent choices for a closed terrarium.
As part of a live terrarium setup, amphipods will quickly make their new environment home, burrowing into the substrate and consuming decaying organic matter. This contributes significantly to the overall health and sustainability of the terrarium ecosystem, breaking down waste that might otherwise accumulate. Their ability to efficiently process waste in a closed system, making them a critical part of any terrarium with insects.
Pond Snails

Pond snails are a fantastic addition to your closed terrarium ecosystem. Not only do they add a different aesthetic element with their delicate, spiral shells and slow movement, but they also have practical uses. They feed on dead plant matter and algae, thus helping prevent mold – a common issue in many closed terrariums. Pond snails can be considered the cleanup crew for your live terrarium.
Maintaining pond snails in a closed terrarium is fairly straightforward. They require high humidity and enough decaying plant matter to feed on. Adding a water feature to your terrarium for animals, if space permits, can create a more habitable environment for the snails, adding another layer of complexity and interest to your terrarium.
Ramshorn Snails

Ramshorn Snails, belonging to the family Planorbidae, are unique freshwater snails characterized by their planispiral shells. Like most terrarium animals, Ramshorn Snails play a significant role in keeping your closed terrarium clean and mold-free. They feed on decaying plant matter and algae, making them fantastic terrarium pets for an enclosed ecosystem.
Ramshorn Snails’ diet, behavior, and role within a terrarium are somewhat similar to pond snails, with their unique shell shape adding an additional point of visual interest. Keeping a balance between the number of snails and the food available is critical to maintain a healthy terrarium ecosystem and prevent overpopulation.
Springtails

Springtails, tiny arthropods named for their spring-loaded tail mechanism, are a fundamental part of any healthy, bioactive terrarium. Their main diet consists of decaying plant matter and mold, making them an integral part of the terrarium’s cleanup crew. As such, they are a boon to your closed terrarium ecosystem, contributing to decomposition and nutrient recycling.
Springtails thrive in moist environments and play a vital role in preventing mold growth in closed terrariums. They are tiny, fast, and often invisible to the naked eye, but their presence can be confirmed by the healthy state of your terrarium. Thus, these creatures are an excellent addition to your terrarium for animals, maintaining balance and health in your closed ecosystem.
Earthworms

Earthworms can be a great addition to your terrarium ecosystem. They are excellent at fertilizing the soil by breaking down organic matter and releasing nutrients. This makes them invaluable in a terrarium environment, contributing to the health of the plants. The only downside is that earthworms might occasionally leave castings on the glass, impacting the visual appeal of the terrarium.
When adding earthworms to a closed terrarium, it’s important to limit their number and keep them away from direct sunlight. They should be kept in a terrarium with a good amount of soil, as they need to burrow. With the right care, earthworms can significantly contribute to the closed terrarium ecosystem’s sustainability.
Millipedes

Millipedes, with their many segmented bodies and slow-moving nature, are a fantastic choice for your terrarium. These arthropods scavenge and eat any decaying matter in your terrarium, ensuring fewer dead leaves, less wood, and other decaying matter. This cleaning action helps maintain balance in your closed terrarium and prevents the growth of mold.
A millipede’s preference for damp, dark places makes them well-suited to a terrarium environment. They are generally easy to care for and can live for several years. Millipedes bring a fascinating element of the invertebrate world into your terrarium, making it a microcosm of the larger world outside. A millipede’s diet and lifestyle make them one of the best terrarium worms you can choose to include in your closed terrariums.
Creating a Closed Terrarium: A Step-by-Step Guide
While watching a closed terrarium ecosystem can be captivating, creating one can be even more rewarding. Here’s a step-by-step guide on how to make a closed terrarium that will thrive with life.
- Selecting the Container: The first step to creating a closed terrarium is choosing the right container. It can be a jar, bottle, fish tank, or anything else that is transparent and can be sealed. The size depends on the types of plants and animals you want to keep.
- Preparing the Base: Layer the bottom of the container with small stones or pebbles. This is crucial for drainage, preventing water from stagnating and causing root rot.
- Adding a Layer of Activated Charcoal: On top of the pebbles, add a thin layer of activated charcoal. This will help purify the water, keeping it fresh and clean.
- The Substrate: On top of the charcoal, add a layer of potting soil or a special terrarium soil. This is where your plants will root.
- Choosing and Planting the Right Plants: When choosing plants for closed terrariums, it’s important to select those that thrive in high humidity and low light conditions. Once you’ve made your choices, you can plant them in the soil.
- Introducing Animals: After setting up the plants, it’s time to add the terrarium animals from our list above. Make sure to research each one and provide the conditions they need to thrive.
- Sealing and Placing the Terrarium: Once everything is set up, you can seal your terrarium and place it in a spot with indirect light.
How to Maintain a Healthy Terrarium
Maintaining a healthy terrarium involves a few simple steps:
- Monitoring: Regularly check your terrarium for signs of disease or discomfort in the inhabitants. Keep an eye out for mold, which can be an issue in closed terrariums.
- Feeding: While a well-set-up terrarium is mostly self-sufficient, it’s good practice to provide supplementary food for your terrarium animals occasionally.
- Pruning and Cleaning: Prune overgrown plants and remove any dead leaves or flowers to prevent decay and disease. Also, clean the glass inside and out for a clear view into your mini ecosystem.
In Conclusion
Creating and maintaining a closed terrarium is a beautiful blend of art, science, and nature. It offers a chance to observe a miniature ecosystem and can serve as an engaging, educational hobby. Whether it’s the cherry shrimp adding a touch of color or the earthworms busily fertilizing the soil, the choice of animals in your terrarium can truly bring it to life.
With the steps and tips provided, along with a dose of patience and care, you can create a flourishing, self-sustaining world within your closed terrarium, a testament to the intricate, fascinating wonder of the natural world.